stream_loop "Seek to start failed" with H.264 rawvideo file

[Serveurperso]

Hello, I'm free to make more testing, just ask.

Summary of the bug:
How to reproduce:
% ffmpeg -i input ... output

./ffmpeg -re -stream_loop -1 -i /tmp/robot.264 -codec copy -f rawvideo tcp://127.0.0.1:8004

ffmpeg version N-90197-gaa294ad Copyright (c) 2000-2018 the FFmpeg developers

built with gcc 4.9.2 (Debian 4.9.2-10+deb8u1)
configuration:
libavutil 56. 8.100 / 56. 8.100
libavcodec 58. 13.100 / 58. 13.100
libavformat 58. 10.100 / 58. 10.100
libavdevice 58. 2.100 / 58. 2.100
libavfilter 7. 12.100 / 7. 12.100
libswscale 5. 0.101 / 5. 0.101
libswresample 3. 0.101 / 3. 0.101

Input #0, h264, from '/tmp/robot.264':

Duration: N/A, bitrate: N/A

Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(progressive), 720x576, 25 fps, 25 tbr, 1200k tbn, 50 tbc

Output #0, rawvideo, to 'tcp://127.0.0.1:8004':

Metadata:

encoder : Lavf58.10.100
Stream #0:0: Video: h264 (Constrained Baseline), yuv420p(progressive), 720x576, q=2-31, 25 fps, 25 tbr, 25 tbn, 25 tbc

Stream mapping:

Stream #0:0 -> #0:0 (copy)

Press [q] to stop, ? for help
Seek to start failed.=-1.0 size= 906kB time=00:00:11.20 bitrate= 662.7kbits/s speed= 1x
/tmp/robot.264: Operation not permitted
frame= 280 fps= 25 q=-1.0 Lsize= 906kB time=00:00:11.20 bitrate= 662.7kbits/s speed= 1x
video:906kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000%

ffmpeg version
built on ...
}}}
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Serveurperso]

Raw H.264 from FFmpeg / V4L2